JP2012161873A - Diamond-coated cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diamond-coated cutting tool exerting excellent wear resistance in cutting of a difficult-to-cut material such as a CFRP material, a high Si contained aluminum alloy and a graphite.SOLUTION: In this diamond-coated cutting tool, a crystalline diamond layer is coated on a surface of a tool base body constituted of tungsten carbide group cemented carbide or titanium carbonitride group cermet, an alternate laminate film in which nanodiamond films having an average particle size of 1-50 nm and crystalline diamond films having an average particle size of 0.1-2 μm are alternately laminated at laminate layer intervals of 0.2-2.0 μm is coated on the crystalline diamond layer, a rake face (or further, a flank) is irradiated with an ultraviolet laser to eliminate the alternate laminate film of the rake face (or further, a flank), and an amorphous carbon film having a surface roughness Ra of ≤0.1 μm and a film thickness of 10-200 nm is formed on a rake face side surface layer (or further a flank side surface layer) of the alternate laminate film forming a cutting edge.

Description

  The present invention is a diamond in which at least a crystalline diamond layer is coated on the surface of a tool base (hereinafter simply referred to as a tool base) composed of a tungsten carbide (WC) base cemented carbide or a titanium carbonitride (TiCN) base cermet. With respect to coated cutting tools, diamond coated cutting that excels in chip evacuation and provides excellent wear resistance over a long period of use, especially when cutting difficult-to-cut materials such as CFRP materials, high Si-containing aluminum alloys, and graphite. The present invention relates to a tool (hereinafter referred to as a diamond-coated tool).

Conventionally, diamond-coated tools with a diamond coating coated on the surface of the tool substrate are known. In order to increase the strength and toughness of the coating, a layer of highly crystalline diamond and microcrystalline diamond (or amorphous diamond) is laminated. Constructing a diamond film as a structure, and a diamond film as a multilayer structure of microcrystalline diamond with a grain size of 2 μm or less for the purpose of improving the surface smoothness of the film and the accuracy of the finished surface of the work material It has been known.
For example, as shown in Patent Document 1, the first layer is a polycrystalline diamond layer having a particle size of 0.1 to 10 μm, and the second layer is a twinned diamond layer having a particle size of 0.05 to 8 μm or a non-crystalline diamond layer. A diamond-coated tool is known in which strength and toughness are improved by forming a diamond film with a laminated structure composed of a crystalline diamond layer.
Further, as shown in Patent Document 2, a nucleus attaching step for attaching a nucleus serving as a starting point for crystal growth of diamond to the surface and a crystal growing step for crystal growing diamond by CVD using the nucleus as a starting point are repeated. Therefore, a diamond coating tool is known in which the diamond film is composed of a multilayer structure of microcrystalline diamond having a crystal grain size of 2 μm or less, thereby improving the surface smoothness of the film and improving the accuracy of the finished surface of the work material. ing.
In addition, as shown in Patent Documents 3 and 4, in a diamond-coated tool including a base on which a cutting edge is formed and a diamond coating film that covers the cutting edge, the coating film is ground to obtain a cutting edge portion. A diamond-coated tool is known in which the finished surface accuracy of a work material is improved by sharply machining the workpiece.
Further, as shown in Patent Document 5, in a diamond-coated tool including a base on which a cutting edge is formed and a diamond coating film that covers the cutting edge, the blade edge is irradiated with ultraviolet laser light on the coating film. There is known a diamond-coated tool capable of processing graphite, aluminum alloy and the like with high precision by processing a portion sharply.

JP-A-4-236797 Japanese Patent No. 3477162 Japanese Patent No. 3477182 Japanese Patent No. 3477183 JP 2009-6436 A

  In recent years, cutting accuracy of difficult-to-cut materials such as CFRP, high Si content Al alloy, and graphite has come to require processing accuracy, and it is necessary to sharpen the cutting edge in order to improve processing accuracy. There is.

  For example, in the cutting of difficult-to-cut materials using diamond-coated tools shown in Patent Documents 1 and 2, since the diamond film wears quickly, it is necessary to increase the film thickness of the diamond film. When the thickness is increased, it becomes difficult to form a sharp cutting edge, which causes a problem that the processing accuracy is lowered.

  In addition, although a cutting tool made of a diamond sintered body has better wear resistance than a diamond-coated tool, it is difficult to form a sharp cutting edge. Have difficulty.

  In the diamond-coated tools shown in Patent Documents 3 to 5, since a sharp cutting edge is formed, an improvement in processing accuracy can be expected, but the diamond film on the cutting edge is brittle and easily generates chipping. There is a problem that the lifetime is short.

  Therefore, the present inventors have excellent machining accuracy and chip discharge performance without generating chipping even when used for cutting difficult-to-cut materials such as CFRP, high Si content Al alloy, and graphite. As a result of diligent research to develop a diamond-coated tool that exhibits excellent wear resistance, the following findings were obtained.

  That is, a crystalline diamond layer having a predetermined thickness is coated on the surface of a tool base made of a WC-based cemented carbide or TiCN-based cermet, and an alternate laminated film composed of nanodiamond and crystalline diamond is further coated thereon. After the formation, for example, by irradiating the surface of the rake face with an ultraviolet laser and irradiating and removing the alternate laminated film other than the cutting edge, a sharp cutting edge covered with the crystalline diamond layer and the alternate laminated film is obtained. In addition, a diamond-coated tool is formed by forming a smooth amorphous carbon film in which a part of nanodiamond is modified by an ultraviolet laser on the rake face side surface of the alternately laminated film of cutting edges. It has a cutting edge with excellent wear resistance, toughness, chipping resistance, lubricity, and chip evacuation, which results in long-term use in cutting difficult-to-cut materials. Over, it exhibits excellent wear resistance, it is the tool life was found to be significantly longer life. Furthermore, by irradiating the surface of the flank with an ultraviolet laser and irradiating and removing the alternate laminated film other than the cutting edge, a sharp cutting edge covered with the crystalline diamond layer and the alternating laminated film is formed, In addition, by forming a smooth amorphous carbon film in which a part of diamond has been modified by an ultraviolet laser on the surface layer on the flank side of the alternately laminated film of cutting edges, the diamond-coated tool is resistant to wear and toughness. It has a cutting edge with excellent chipping resistance and lubricity, and a flank surface with excellent frictional resistance. As a result, it exhibits superior wear resistance over long-term use in cutting difficult-to-cut materials. It has been found that the tool life is greatly prolonged.

This invention has been made based on the above findings,
“(1) In a diamond-coated cutting tool in which a crystalline diamond layer having a layer thickness of 3 to 30 μm is coated on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
On the surface of the crystalline diamond layer of the cutting edge of the diamond-coated cutting tool, a nanodiamond film having an average particle diameter of 1 to 50 nm and a crystalline diamond film having an average particle diameter of 0.1 to 2 μm are 0.2 to 2. . The alternate distance between the cutting edge composed of the alternate laminated films and the crystalline diamond layer is 3 to 15 micrometers, and the alternate laminated films are alternately laminated at a lamination interval of 0.0 μm. The diamond-coated cutting is characterized in that an amorphous carbon film having a surface roughness Ra of 0.1 μm or less and a film thickness of 10 to 200 nm is formed on the surface layer of the rake face side of the alternately laminated film of cutting edges. tool.

  (2) On the surface of the crystalline diamond layer on the flank face of the diamond-coated cutting tool, a nanodiamond film having an average particle diameter of 1 to 50 nm and a crystalline diamond film having an average particle diameter of 0.1 to 2 μm are 0.00. The diamond-coated cutting tool as described in (1) above, wherein the alternately laminated films alternately laminated at a lamination interval of 2 to 2.0 μm are coated.

(3) An amorphous carbon film having a surface roughness Ra of 0.1 μm or less and a film thickness of 10 to 200 nm is formed on the flank surface layer of the alternately laminated film of cutting edges of the diamond-coated cutting tool. The diamond-coated cutting tool according to (1) above, wherein "
It is characterized by.

Hereinafter, the present invention will be described in detail.
Crystalline diamond layer:
In this invention, the layer thickness of the crystalline diamond layer coated on the surface of the tool substrate made of WC cemented carbide (examples of the composition is shown in Table 1, for example) or TiCN-based cermet is defined as 3 to 30 μm. However, if the layer thickness is less than 3 μm, it is not possible to exhibit excellent wear resistance over a long period of use, while if the layer thickness of the crystalline diamond layer exceeds 30 μm, the crystal grains tend to be coarsened, In this invention, the thickness of the crystalline diamond layer is determined to be 3 to 30 μm because not only the defect resistance is deteriorated but also peeling easily occurs.
Alternate laminated film of cutting edges:
The cutting edge of the diamond-coated tool of the present invention is formed by coating an alternating multilayer film in which nano-diamond films and crystalline diamond films are alternately stacked on the surface of the crystalline diamond layer.

  The method for forming the alternating laminated film of cutting edges is, for example, as follows.

  As shown in FIG. 1, first, a crystalline diamond layer (1) having a layer thickness of 3 to 30 μm is coated on the surface of the tool base (9), and then an average particle diameter of 1 to 50 nm is further formed thereon. An alternate laminated film (2) made of nano diamond and crystalline diamond having an average particle diameter of 0.1 to 2.0 μm is formed by coating (examples of film forming conditions are shown in Table 2, for example). The alternate laminated film (2) is laminated so that the lamination interval is 0.2 to 2.0 μm.

Next, for example, an ultraviolet laser is irradiated from the leading edge (4) of FIG. 1 to A to irradiate and remove the alternate laminated film (2) formed on the rake face other than the cutting edge as shown in FIG.
Further, the shortest distance (7) from the leading edge (4) of the alternately laminated film of cutting edges to the crystalline diamond layer is 3 to 15 μm.
Here, when the intersection line between the virtual extension surface of the rake face and the virtual extension surface of the flank face is the virtual tip, the tip of the alternate laminated film located closest to the virtual tip (that is, the distance from the virtual tip is The tip of the shortest alternating laminated film is defined as “the most advanced” in the present invention.

In other words, by irradiating with ultraviolet laser, a sharp cutting edge covered with an alternating laminated film is formed on the cutting edge, and a part of diamond is formed on the rake face side surface of the alternating laminated film of the cutting edge by ultraviolet laser. A smooth amorphous carbon film with a modified surface is formed, and a cutting edge excellent in wear resistance, toughness, chipping resistance, lubricity, and chip dischargeability is formed.
As shown in FIG. 3, the distance (5) from the cutting edge (4) of the cutting edge of the rake face to the crystalline diamond layer exposed on the rake face is preferably 5 to 25 μm.

  Here, when the average particle diameter of the nanodiamond constituting the above-mentioned alternately laminated film is less than 1 nm, the wear resistance is lowered. On the other hand, when it exceeds 50 nm, chipping is likely to occur. It was determined to be 1 to 50 nm.

  In addition, when the average grain size of the crystalline diamond constituting the alternating laminated film is less than 0.1 μm, the wear resistance is lowered, and when it exceeds 2.0 μm, the crystal grains are coarsened and chipping and peeling occur. Therefore, the average particle diameter of the crystalline diamond was determined to be 0.1 to 2.0 μm.

  Further, when the stacking interval of the alternate laminated film is less than 0.2 μm, the wear resistance is deteriorated. On the other hand, when it exceeds 2.0 μm, chipping is likely to occur. It was determined to be 2.0 μm.

  When cutting a CFRP with a diamond-coated drill, if the cutting edge is composed of a single layer of crystalline diamond, the crystal grains are large and the toughness is low. Caused delamination in the work material. In the case of a single layer of nanodiamond, although it has high fracture resistance, it has insufficient wear resistance, so that the cutting edge is worn away and the sharpness is lowered, and similarly, delamination occurs in the CFRP material. Therefore, by providing the cutting blade with an alternating multilayer film in which nano diamond and crystalline diamond are laminated, the toughness of the cutting edge is improved, so that chipping and chipping are less likely to occur, and sufficient wear resistance can be provided. became.

  The alternate laminated film once formed on the crystalline diamond layer on the rake face is removed by the laser irradiation described above. In particular, the diamond of the alternate laminated film is applied to the surface layer on the rake face side of the alternate laminated film of the cutting edge. Partially modified to form an amorphous carbon film having a surface roughness of 0.1 μm or less and a film thickness of 10 to 200 nm.

  Here, when the surface roughness Ra of the amorphous carbon film exceeds 0.1 μm, chip dischargeability is lowered, so the surface roughness Ra of the amorphous carbon film is determined to be 0.1 μm or less. It was.

Further, when the amorphous carbon film has a thickness of less than 10 nm, the lubricity cannot be maintained over a long period of use, and thus the chip dischargeability is not sufficient. On the other hand, when the film thickness of the amorphous carbon film exceeds 200 nm, the wear resistance tends to decrease. Therefore, the film thickness of the amorphous carbon film is determined to be 10 to 200 nm.
In rough machining, it is important to achieve both sharpness and fracture resistance. Therefore, even if only the rake face is laser machined, the sharpness can be improved and the tool life can be extended. Further, as shown in FIG. 3, for example, the alternating laminated film formed on the rake face other than the cutting edge and the flank face is irradiated with an ultraviolet laser from the leading edge (4) to A and the leading edge (4) to B in FIG. As shown in FIG. 3, a sharper cutting edge covered with the alternating laminated film is formed on the cutting edge as shown in FIG. 3, and the surface layer on the rake face side and the flank side of the alternating laminated film of the cutting edge are formed. On the surface layer, a smooth amorphous carbon film in which a part of diamond is modified by an ultraviolet laser is formed. In this case, the distance from the cutting edge of the rake face (4) to the crystalline diamond layer exposed on the rake face (5) and the cutting edge of the flank face (4) to the flank face. The distance (8) to the exposed crystalline diamond layer is preferably 5 to 25 μm. Laser machining of the flank face in addition to the rake face will slightly reduce the toughness of the cutting edge, but the sharpness will be further improved. There is a case. The amorphous carbon layer formed on the surface during laser processing contributes to improved chip evacuation on the rake face, and reduces the frictional resistance with the workpiece on the flank face, improving the processing accuracy. .

  In addition, as shown in FIGS. 2 and 3, the shape and size of the alternately laminated film formed on the cutting edge is the shortest distance (7) from the cutting edge (4) to the crystalline diamond layer, that is, alternately. The film thickness of the laminated film is set to 3 to 15 μm.

  This is because the sharpest cutting edge cannot be formed if the shortest distance from the cutting edge to the crystalline diamond layer is less than 3 μm, so it is expected to improve and maintain the processing accuracy over a long period of use. On the other hand, if the distance exceeds 15 μm, chipping is likely to occur.

Formation of the crystalline diamond layer on the surface of the tool substrate is, for example,
Filament temperature 2300 ° C,
Substrate temperature 800 ° C,
Reaction pressure 30 Torr,
Reaction gas flow rate CH ₄ : 80 sccm, H ₂ : 3000 sccm,
A film can be formed by vapor deposition by the hot filament method under the conditions described above.

Moreover, the film formation of the alternating laminated film is, for example,
Filament temperature 2200 ° C,
Substrate temperature 700 ° C,
Reaction pressure 8 Torr,
Reaction gas _{CH 4: 60sccm, H 2:} 1500sccm,
After depositing a nanodiamond film to a predetermined thickness by the hot filament method of the conditions of
A crystalline diamond film having a predetermined thickness is vapor-deposited under the same conditions as those for forming the crystalline diamond layer, and the nano diamond film and the crystalline diamond film are formed to have a predetermined alternating laminated film thickness. Films can be formed by alternately repeating the process until it becomes.

In the diamond-coated tool of the present invention, a crystalline diamond layer is coated on the surface of a tool base, and an alternating laminated film having a predetermined shape and size composed of a nanodiamond film and a crystalline diamond film is formed on the cutting edge. In addition, an amorphous carbon film with a specified surface roughness and thickness is formed on the surface layer on the rake face side of the alternating laminated film of cutting edges after processing by laser. In addition, it has excellent properties for chip discharge. In addition, by applying laser processing to the flank, an amorphous carbon film is also formed on the surface of the flank side of the alternating laminated film of cutting edges, showing a sharp cutting edge and excellent lubricity and chip discharge. It has the effect of reducing the frictional resistance with the workpiece and improving the machining accuracy.
Therefore, even when used for cutting difficult-to-cut materials such as CFRP, high Si content Al alloy, graphite, etc., it has excellent machining accuracy and chip discharge without generating chipping, and excellent wear resistance over a long period of use. The tool has a long service life.

The schematic cross-sectional schematic diagram of the film | membrane structure of the cutting edge vicinity which consists of the crystalline diamond layer before laser processing of the diamond-coated tool of this invention and an alternating laminated film is shown. The schematic cross-sectional schematic diagram of the film | membrane structure of the cutting edge vicinity after carrying out the laser processing of the rake face of the diamond-coated tool of this invention is shown. The schematic cross-sectional schematic diagram of the film | membrane structure of the cutting edge vicinity after carrying out the laser processing of the rake face and flank face of the diamond-coated tool of this invention is shown.

  Next, the diamond-coated tool of the present invention will be specifically described with reference to examples.

  Here, an example when used as an insert for cutting an Al alloy and an example when used as a drill for cutting CFRP are shown, but the present invention is not limited to this, and various types of end mills and the like are used. It can also be applied to cutting tools. Particularly, in cutting CFRP with a diamond-coated drill, in addition to the sharpness of the cutting edge, toughness and wear resistance are required for the cutting edge, the tool of the present invention is suitable for a diamond-coated drill for CFRP cutting.

As raw material powders, WC powder, TiC powder, TaC powder, NbC powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared, and these raw material powders are blended in the blending composition shown in Table 1, Wet-mix for 96 hours with a ball mill, dry, and press-mold into a green compact at a pressure of 100 MPa. The green compact is sintered in a 6 Pa vacuum at a temperature of 1400 ° C. for 1 hour and polished. By machining and mirror-finishing the rake face of the cutting edge, cemented carbide substrates 1 to 10 each made of a WC-based cemented carbide and having an ISO standard / SPGN12308 insert shape were produced.
(A) The cemented carbide substrates 1 to 10 are charged into a CVD apparatus. First, under the conditions shown in Table 2, a predetermined average layer thickness is formed on the cutting edge, rake face and flank of the substrates 1 to 10. , Depositing a crystalline diamond layer with an average grain size,
(B) Next, a nanodiamond film having a predetermined average film thickness and an average particle diameter is vapor-deposited under the same conditions as shown in Table 2, and a predetermined average film thickness under the same conditions as shown in Table 2 By depositing a crystalline diamond film having an average particle size and alternately repeating the deposition of the nano diamond film and the deposition of the crystalline diamond film, a predetermined edge is formed on the cutting edge, rake face, and flank face of the substrates 1 to 10. Vapor deposition of alternating laminated films with average film thickness
(C) Next, the cemented carbide substrate on which the crystalline diamond layer and the alternate laminated film are vapor-deposited is mounted on a laser processing apparatus, a laser light source of an ultraviolet laser (wavelength: 262 nm) is driven, and a focus lens is an ultraviolet laser. The laser beam is focused at a position that overlaps the center of the sample stage, and then the sample stage is moved to irradiate the ultraviolet laser to the cutting edge, and the laser is applied to the rake face by a galvano scanner. By scanning, remove the alternate laminated film other than the cutting edge of the rake face,
(D) On the cutting edge, a crystalline diamond layer and an alternate laminated film shown in Table 3 are formed so as to cover, and an amorphous carbon film shown in Table 6 is formed on the rake face side of the alternate laminated film.
(E) Moreover, about the base | substrates 1-5, the alternate laminated film other than the cutting edge of a flank is further removed by grind | polishing the cutting edge of a flank.

  As described above, according to (a) to (e), an amorphous carbon film is formed on the cutting edge on the rake face side, the cutting edge on the flank face is polished, and the cutting edge on the flank face side is formed of an alternately laminated film. The invention coated tools (inserts) 1 to 5 as the diamond coated tool of the present invention corresponding to claim 1 in which only the crystalline diamond layer is coated on the flank other than the cutting edge were manufactured.

  Further, according to (a) to (d), the amorphous carbon film is formed on the cutting edge on the rake face side, and the crystalline diamond layer and the alternating laminated film are coated on the flank face. Corresponding invention coated tools (inserts) 6 to 10 were produced.

For comparison,
(A ′) The cemented carbide bases 1 to 10 are charged into a CVD apparatus. First, under the conditions shown in Table 4, a predetermined average layer thickness and average are formed on the cutting edge, rake face, and flank face of the base. Depositing a crystalline diamond layer of grain size,
(B ′) Next, a nanodiamond film having a predetermined average film thickness and average particle diameter is vapor-deposited under the same conditions as shown in Table 4, and a predetermined average film thickness is also formed thereon under the same conditions as shown in Table 4. By depositing a crystalline diamond film having an average particle diameter and alternately depositing a nanodiamond film and a crystalline diamond film, a predetermined average film is formed on the cutting edge, rake face, and flank face of the substrate. Vapor deposition of thick alternating layers
(C ′) Next, the cemented carbide substrate on which the crystalline diamond layer and the alternating laminated film are vapor-deposited is mounted on a laser processing apparatus, a laser light source of an ultraviolet laser (wavelength: 262 nm) is driven, and a focus lens is made ultraviolet. Move in the direction of the laser's optical axis, collect the ultraviolet laser beam at a position that overlaps the center of the sample stage, then move the sample stage, irradiate the ultraviolet laser to the cutting edge, and rake the laser with a galvano scanner By scanning to remove the alternate laminated film other than the cutting edge,
(D ′) The cutting edge and flank face of the rake face are coated with a crystalline diamond layer and an alternating laminated film shown in Table 5, and the amorphous layer shown in Table 6 is formed on the surface layer on the rake face side of the alternating laminated film. A carbon film is formed.
(E ′) Further, with respect to a part of those obtained in the above (a ′) to (d ′), an alternate laminated film other than the flank cutting edge is further polished by polishing the flank cutting edge. Remove.

  As described above, according to (a ′) to (e ′), the amorphous carbon film is formed on the cutting edge on the rake face side, the cutting edge on the flank face is polished, and the cutting edges on the flank face are alternately laminated films. Comparative coating tools (inserts) 1 to 6 are manufactured as comparative diamond coated tools in which only the crystalline diamond layer is coated on the flank other than the cutting edge, and (a ′ ) To (d ′), an amorphous carbon film is formed on the cutting edge on the rake face side, and a crystalline diamond layer and an alternating laminated film are formed on the flank face as a comparative diamond-coated tool. Comparative coated tools (inserts) 8 to 15 were produced.

  For the comparative coated tool (insert) 7, the alternate laminated film was not formed.

  For the inventive coated tools 1 to 10 and comparative coated tools 1 to 15 obtained as a result, the film thickness of each of the above films and the layer thickness of the crystalline diamond layer were measured using a scanning electron microscope (longitudinal section measurement). ), All showed an average layer thickness (average value of five-point measurement) substantially the same as the target layer thickness.

Further, the crystallinity of the surface layer film on the rake face side of the cutting edge was evaluated from the half width at the Raman peak of 1333 cm ⁻¹ by Raman spectroscopic analysis using visible light obtained from an Ar gas laser. The surface roughness Ra of the surface layer film on the rake face side of the cutting edge was measured with a laser microscope. The average particle diameter of diamond was calculated by dividing a line segment parallel to the interface by the total number of diamond particles in the line segment. Furthermore, the shortest distance from the most advanced alternate laminated film to the crystalline diamond layer was measured with a microscope after the sample was processed in cross section.

  Tables 3, 5, and 6 show these results.

つぎに、上記の本発明被覆工具１〜１０および比較被覆工具１〜１５を工具鋼製バイトの先端部に固定治具にてネジ止めした状態で、ＪＩＳ・Ａ４０３２（組成は、質量％で、Ａｌ−１２％Ｓｉ）からなる丸棒を被削材として、表７に示す切削条件１、切削条件２で高Ｓｉ含有Ａｌ合金の乾式連続高速切削加工試験を行なった。

Next, in the state where the present invention coated tools 1 to 10 and the comparative coated tools 1 to 15 are screwed to the tip of the tool steel tool with a fixing jig, JIS A4032 (composition is mass%, Using a round bar made of Al-12% Si) as a work material, a dry continuous high-speed cutting test of a high Si-containing Al alloy was performed under cutting conditions 1 and 2 shown in Table 7.

  In any cutting test, the flank wear width of the cutting edge was measured.

  Table 8 shows the measurement results.

表８に示される結果から、この発明のダイヤモンド被覆工具は、難削材の切削に用いた場合でも、チッピングを発生することなく、加工精度、切屑排出性にすぐれ、長期の使用にわたってすぐれた耐摩耗性を発揮するのに対して、比較被覆工具１〜１５は、耐チッピング性、耐摩耗性が劣り、切削性能が満足できるものでないことは明らかである。
次に本発明のダイヤモンドコーティングドリルを使用することによるバリ抑制の効果について調べた。
下記仕様のドリルを使用して、表２および表４の成膜条件でダイヤモンド膜をドリルに成膜し、紫外線レーザを用いてドリルの切れ刃のすくい面を加工した。ダイヤモンド被覆工具を用いて、バリが発生するまで貫通穴の数を調査した。
使用ドリル：外径φ６ｍｍ、２枚刃、Ｃｏ６wt% 超硬合金製ドリル
切削条件：切削速度Ｖ＝６０ｍ／ｍｉｎ、送りｆ＝０．０５ｍｍ／ｒｅｖ
被削材：ＣＦＲＰ（厚み２０ｍｍ）
試験結果を表９に示す。

From the results shown in Table 8, the diamond-coated tool according to the present invention has excellent machining accuracy and chip discharge characteristics without causing chipping even when used for cutting difficult-to-cut materials. It is clear that the comparative coated tools 1 to 15 are inferior in chipping resistance and wear resistance and are not satisfactory in cutting performance while exhibiting wear.
Next, the effect of suppressing burrs by using the diamond coating drill of the present invention was investigated.
Using a drill with the following specifications, a diamond film was formed on the drill under the film formation conditions shown in Tables 2 and 4, and the rake face of the drill's cutting edge was processed using an ultraviolet laser. Using a diamond-coated tool, the number of through holes was investigated until burrs were generated.
Drill used: outer diameter φ 6 mm, 2-flute, Co 6 wt% cemented carbide drill Cutting conditions: Cutting speed V = 60 m / min, Feed f = 0.05 mm / rev
Work material: CFRP (thickness 20mm)
The test results are shown in Table 9.

表９に示される結果から、本発明工具６〜１０は本発明被覆工具１〜５に比べ、切れ刃のシャープさがない分、切削寿命が短くなっているが、ＣＦＲＰの切削性能を十分に満足することを示した。本発明のダイヤモンド被覆工具は、ＣＦＲＰの切削に用いた場合でも、長期の使用にわたって、バリを発生することなく、加工精度、切屑排出性にすぐれ、すぐれた耐摩耗性を発揮するのに対して、比較被覆工具７〜１５は、耐チッピング性、耐摩耗性が劣り、バリが早期に生じることから、切削性能が満足できるものでないことは明らかである。比較被覆工具１〜６は比較被覆工具７〜１５より、刃先がシャープなため工具寿命が延びているものの、チッピングなどの要因により、切削性能を満足できるものではないないことは明らかである。

From the results shown in Table 9, the inventive tools 6 to 10 have a shorter cutting life than the inventive coated tools 1 to 5 due to the lack of sharpness of the cutting edge, but the cutting performance of CFRP is sufficient. Showed satisfaction. The diamond-coated tool of the present invention exhibits excellent processing accuracy, chip dischargeability, and excellent wear resistance without generating burrs over a long period of use, even when used for CFRP cutting. Since the comparative coated tools 7 to 15 are inferior in chipping resistance and wear resistance, and burrs are generated early, it is clear that the cutting performance is not satisfactory. Although the comparative coated tools 1 to 6 have a longer tool life than the comparative coated tools 7 to 15 due to their sharp edges, it is clear that the cutting performance is not satisfactory due to factors such as chipping.

(A) The cemented carbide substrate on which the crystalline diamond layer and the alternating laminated film formed in Example 1 are vapor-deposited is mounted on a laser processing apparatus, and a laser light source of an ultraviolet laser (wavelength: 262 nm) is driven. Move the focus lens in the direction of the optical axis of the ultraviolet laser, focus the ultraviolet laser light at a position that overlaps the center of the sample stage, then move the sample stage to make the ultraviolet laser rake face and flank other than the cutting edge , And by scanning the laser with a galvano scanner, the alternate laminated film of the surface layer other than the cutting edge of the rake face and the flank face is removed,
(B) The cutting edge is coated with a crystalline diamond layer and an alternating laminated film shown in Table 10, and the amorphous layer shown in Table 11 is formed on the surface layer on the rake face side and the flank side of the alternating laminated film. A quality carbon film was formed.

  As described above, according to (a) to (b), the present invention coated tool (insulator) as the diamond coated tool according to the present invention corresponding to the present invention 3 in which the amorphous carbon film is formed on the surface of the cutting edge of the rake face and the flank face. -G) 11-20 were manufactured.

For comparison,
(A ') Insert the cemented carbide substrate of Table 1 into a CVD apparatus, first, under the conditions shown in Table 4, vapor-deposited a crystalline diamond layer having a predetermined average layer thickness and average particle diameter,
(B ′) Next, a nanodiamond film having a predetermined average film thickness and average particle diameter is vapor-deposited under the same conditions as shown in Table 4, and a predetermined average film thickness is also formed thereon under the same conditions as shown in Table 4. , By depositing a crystalline diamond film having an average grain size, and alternately depositing a nanodiamond film and depositing a crystalline diamond film to form an alternately laminated film having an average film thickness in Table 12,
(C ′) The cemented carbide substrate on which the crystalline diamond layer and the alternating laminated film of Table 12 are vapor-deposited is mounted on a laser processing apparatus, the laser light source of the ultraviolet laser (wavelength: 262 nm) is driven, and the focus lens is made ultraviolet. Move in the optical axis direction of the laser, collect the ultraviolet laser light at a position overlapping the center of the sample stage, then move the sample stage and irradiate the rake surface and flank other than the cutting edge with the ultraviolet laser, By scanning the laser with a galvano scanner, the alternate laminated film other than the cutting edge is removed,
(D ′) The cutting edge is coated with a crystalline diamond layer and an alternating laminated film shown in Table 12, and the amorphous layer shown in Table 13 is formed on the rake face and flank side of the alternating laminated film. A quality carbon film was formed.

  As described above, according to (a ′) to (d ′), the comparative coated tool (insert) 21 as a comparative diamond coated tool in which an amorphous carbon film is formed on the surfaces of the rake face and the flank cutting edge. 26, 28-35 were produced.

  The comparative coated tool (insert) 27 was not subjected to the formation of the alternating laminated film and the processing by the laser.

つぎに、上記の本発明被覆工具１１〜２０を工具鋼製バイトの先端部に固定治具にてネジ止めした状態で、ＪＩＳ・Ａ４０３２（組成は、質量％で、Ａｌ−１２％Ｓｉ）からなる丸棒を被削材として、表７に示す切削条件１、切削条件２で高Ｓｉ含有Ａｌ合金の乾式連続高速切削加工試験を行なった。

Next, in a state where the above-described coated tools 11 to 20 of the present invention are screwed to the tip of the tool steel tool with a fixing jig, from JIS A4032 (composition is mass%, Al-12% Si). A dry continuous high-speed cutting test of a high Si-containing Al alloy was performed under the cutting conditions 1 and 2 shown in Table 7 using the round bar as a work material.

  In any cutting test, the flank wear width of the cutting edge was measured.

  Table 14 shows the measurement results.

次に本発明のダイヤモンドコーティングドリルを使用することによるバリ抑制の効果について調べた。
使用ドリル：外径φ６ｍｍ、２枚刃、Ｃｏ６wt% 超硬合金製ドリル
切削条件：切削速度Ｖ＝６０ｍ／ｍｉｎ、送りｆ＝０．０５ｍｍ／ｒｅｖ
被削材：ＣＦＲＰ（厚み２０ｍｍ）
試験結果を表１５に示す。

Next, the effect of suppressing burrs by using the diamond coating drill of the present invention was investigated.
Drill used: outer diameter φ 6 mm, 2-flute, Co 6 wt% cemented carbide drill Cutting conditions: Cutting speed V = 60 m / min, Feed f = 0.05 mm / rev
Work material: CFRP (thickness 20mm)
The test results are shown in Table 15.

表１４に示される結果から、この発明のダイヤモンド被覆工具は、難削材の切削に用いた場合でも、チッピングを発生することなく、加工精度、切屑排出性にすぐれ、長期の使用にわたってすぐれた耐摩耗性を発揮するのに対して、比較被覆工具２１〜３５は、耐チッピング性、耐摩耗性が劣り、切削性能が満足できるものでないことは明らかである。
また、表１５に示される結果から、この発明のダイヤモンド被覆工具は、ＣＦＲＰの切削に用いた場合でも、長期の使用にわたって、バリを発生することなく、加工精度、切屑排出性にすぐれ、すぐれた耐摩耗性を発揮するのに対して、比較被覆工具２１〜３５は、耐チッピング性、耐摩耗性が劣り、バリが早期に生じることから、切削性能が満足できるものでないことは明らかである。

From the results shown in Table 14, the diamond-coated tool of the present invention has excellent machining accuracy and chip discharge characteristics without causing chipping even when used for cutting difficult-to-cut materials, and excellent resistance to long-term use. It is clear that the comparative coated tools 21 to 35 are inferior in chipping resistance and wear resistance and are not satisfactory in cutting performance while exhibiting wear characteristics.
Further, from the results shown in Table 15, the diamond-coated tool of the present invention was excellent in processing accuracy and chip dischargeability without generating burrs over a long period of use even when used for cutting CFRP. In contrast to the wear resistance, the comparative coated tools 21 to 35 are inferior in chipping resistance and wear resistance, and burrs are generated early, so that it is clear that the cutting performance is not satisfactory.

  As described above, the diamond-coated tool of the present invention has excellent lubricity, chip evacuation and excellent wear resistance, such as CFRP, high Si content Al alloy, and graphite that require high processing accuracy. In cutting difficult-to-cut materials, excellent cutting performance is demonstrated over a long period of use.

DESCRIPTION OF SYMBOLS 1 Crystalline diamond layer 2 Alternating laminated film 3 Cutting edge tip 4 Cutting edge 5 Distance from cutting edge to crystalline diamond layer 6 Amorphous carbon film 7 Shortest distance from cutting edge to crystalline diamond layer 8 Distance from the most advanced flank to the crystalline diamond layer 9 Tool base

Claims (3)

In a diamond-coated cutting tool in which a crystalline diamond layer having a layer thickness of 3 to 30 μm is coated on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
On the surface of the crystalline diamond layer of the cutting edge of the diamond-coated cutting tool, a nanodiamond film having an average particle diameter of 1 to 50 nm and a crystalline diamond film having an average particle diameter of 0.1 to 2 μm are 0.2 to 2. . The alternate distance between the cutting edge composed of the alternate laminated films and the crystalline diamond layer is 3 to 15 micrometers, and the alternate laminated films are alternately laminated at a lamination interval of 0.0 μm. The diamond-coated cutting is characterized in that an amorphous carbon film having a surface roughness Ra of 0.1 μm or less and a film thickness of 10 to 200 nm is formed on the surface layer of the rake face side of the alternately laminated film of cutting edges. tool.   On the surface of the crystalline diamond layer on the flank face of the diamond-coated cutting tool, a nanodiamond film having an average particle diameter of 1 to 50 nm and a crystalline diamond film having an average particle diameter of 0.1 to 2 μm are 0.2 to 2. The diamond-coated cutting tool according to claim 1, wherein the alternately laminated films alternately laminated at a lamination interval of 0.0 μm are coated.   An amorphous carbon film having a surface roughness Ra of 0.1 μm or less and a film thickness of 10 to 200 nm is formed on a surface layer of the flank face of the alternately laminated film of the cutting edges of the diamond-coated cutting tool. The diamond-coated cutting tool according to claim 1.

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